Nitrocellulose gel and method of producing



Patented May 14, 1935' K. 'Shankwei len Newport, and Walter Gloor, Wilmington; l )el.,,assignors to Hercules Powder Company; Wilmington, net, s corporatiiii'i of Delaware Ne Drawing. Application April 29; 1932.

Serial No. 608,340

, r 18 Claims. This invention relates to an improvement in nitrocellulose gels, such, for example, as so -called solidified alcohol used for fuel purposes, and method of producing.

Heretofore it'has been known to produce a nitrocellulose gel, as, for example, solidified al cohol,- by dissolving an alcohol-soluble type of nitrocellulose in an alcohol at low temperature and bringing the resulting solution to a water content of about On bringingthe mixture to room temperature the mixture gels.

Nitrocellulose gels as heretofore composed and produced have not proved satisfactory, since they are inherently unstable, and on exec-sure to inod= crate temperatures will liquefy irreversibly. Lid:- uefaction or syneresis can also be brought about by relatively slight mechanical agitationo'f the gel.

The lack of stability of nitrocellulose gels" as heretofore produced is disadvantageous, due to the fact that by virtue of syner'esis the'geloften reaches the consumer in a partially liquid con: dition, in which condition the product will not burn evenly Further the Iack'of' stability re: vents the marketing of the produc't'inthe con-'- venient tube form, since mechanical agitation of the product approximating that to which it would :be subjected-it packed into tubes will cause syneresis'.

Now it is the object of this invention to pro: vide combustible nitroce'ilulo'se' gel, ofjsalid'ified' fuel, freein large measurefrom synere'sis or from a tendencyto liquefy toffioderate' temperatures and on mechanical agitatibm and In onepracticbl-adaptatiort of this invention the gel is formed by the addition to a substantially anhydrous solution of nitrocellulose in a suitable solvent, of (a) a metal, alloy or mixture of metals or alloys and (b) a salt in relatively small amounts, either the metal, etc., containing copper or the salt being a copper salt, the procedure being carried out at room temperature.

In preparing one form of nitrocellulose gel in accordance with this invention the nitrocellulose may be of any desired type as to nitrogen content, viscosity, etc., but will desirably be of the type or types used heretofore in making solidified alcohol. The alcohol may be of any desired type adaptable for fuel, asisopropyl, ethyl, methyl, and the like, or mixtures of alcohols.

As the metal, alloy or mixture of metals or alloys, which will desirably be in powdered form, one may use, for example, fine copper dust, copper-containing bronze powders, zinc dust, aluminum powder, etc., etc.,awhile as the salt one may use, for example, a halogen salt, an acetate, sul-' fate, etc., as, for example, a chloride bromide," acetate or the like of copper, iron, zinc, aluminum, mercury, nickel, chromium, cobalt, manganese, calcium, magnesium; etc., etc., or mixtures thereof.

It will be noted that either the metal," etc., or the salt, or both, will contain copper. Oth'erwlsi':

the gelling agents and the amounts and relative '0 proportions thereof may be chosen within wide limits, it being only desirable to keep the amount" of the gelling agents at a minifnmn eensistefnt with obtaining gels o1"- inaximum desirdstability'.

As more specifically illustrative of the practical 5' adaptation of this invention gels of Sta bility may be made on the fol-lowing formulae:

Formula A Partsby a weight Alcohol soluble 4o 'secofidnitrocelliilosi-n in Anhydrous ethyl al'cohoL; .0 Copper bronze powder (I4 Instead of using anhydrous ethyl alcohol, as in the above examples, we may use in place thereof acetone, ethyl-methyl ketone, diethyl ketone, etc., methyl, ethyl, isopropyl acetate, or mixtures 45 of ethyl ether, isopropyl ether, etc. with any suitable monohydric alcohol. Thus, for example, any of the above solvents may be substituted in Formula A for the anhydrous ethyl alcohol used therein.

In making up the gels according to the above formulae, for example, the nitrocellulose will be dissolved in a part of the solvent and the copper bronze powder thoroughly agitated into the solution formed, then the copper chloride in solution lulose solvent, nitrocellulose, a metal non-reactive with the nitrocellulose solvent and copper in the remaining solvent added and mixed in, all without cooling or at room temperature, say a temperature within about the range 15-30 C. The gelling will occur, at room temperature, in

' from one-half to eighteen hours depending upon the amount of gelling agent used, and by way of example will occur in about two hours in the case of Formula A above. 7

The gels, in accordance with this invention, will be found to have high stability, to be remarkably resistant to mechanical action and to be heat reversible if exposed to temperatures below 50 C. The method in accordance with this invention will be found to be simple and economical and to possess the advantage that the entire operation will be carried out at room temperature as compared. with the necessity in prior methods for refrigeration and heating.

It will be understood that where in the claims appended hereto the term copper is used, such is intended to embrace and includecopper metal per se or alloyed and copper salts as equivalents within thescope of this invention.

What we claim and desire to protect by Let ters Patent; is:

1. A stable nitrocellulose gel including nitrocellulose, a nitrocellulose solvent, finely divided metal powder non-reactive with the nitrocellulose solvent and a metallic salt non-reactive with and soluble in the nitrocellulose solvent, either the metallic powder or the metallic salt including copper.

2. A stable nitrocellulose gel including a nitrocellulose solvent, nitrocellulose, copper and a metallic salt non-reactive with respect to and soluble in the nitrocellulose solvent.

3. A stable nitrocellulose gel including a nitro cellulose solvent, nitrocellulose, a metal non-reactive with the nitrocellulose solvent and a copper salt.

4. A nitrocellulose gel including a nitrocellulose solvent, nitrocellulose, copper and a metallic halide soluble in the nitrocellulose solvent.

5. A stable nitrocellulose gel including a nitrocellulose solvent, nitrocellulos'e," copper and a vent.

' 6. A nitrocellulose gel including a nitrocellulose solvent, nitrocellulose, a metal non-reactive with the nitrocellulose solvent and a copper halide.

'7. A stable nitrocellulose gel including a nitrocellulose solvent, nitrocellulose, a metal non-reactive with the nitrocellulose solvent and a copper acetate. I

8. A nitrocellulose gel including a nitrocelchloride.

lose solvent, nitrocellulose, copper bronze and copper chloride.

12. A nitrocellulose gel including a nitrocellulose solvent, nitrocellulose, zinc dust andcopper chloride.

13.'The method'of making a nitrocellulose gel comprising the addition to a solution of nitrocellulose in a solventtherefor, of a finely divided metallicpowder non-reactive with the nitrocellulose solvent and a metallic salt non-reactive with respect to and soluble in the nitrocellulose solvent, one of which contains copper, and allow-' ing the mixture to stand until gelation occurs.

14. The method of making a nitrocellulose g'el comprising the addition at room temperatures to a solution of nitrocellulose in a solvent therefor, of a finely divided metallic, powder nonreactive with the nitrocellulose solvent anda metallic salt non-reactive with respect to and soluble in the nitrocellulose solvent, one of which contains copper, and thereupon allowing the mixture to stand at room temperature until gelation occurs.

15-. The method of making a nitrocellulose gel comprising the addition to a solution of nitrocellulose in a solvent therefor, of a finely. divided metallic powder non-reactive with the nitrocellulose solvent and a metallic salt non-reactive with the nitrocellulose solvent in solution in a solventv miscible with the nitrocellulose solvent, .one of the said powder and the said salt containing copper,

and, allowing the mixture to stand until gelation occurs.

16. A stable nitrocellulose gel including a nitrocellulose solvent, nitrocellulose, copper and a metallic sulphatenon-reactive with respect to and soluble in the nitrocellulose solvent.

17 A stable nitrocellulose gel including a nitrocellulose solvent, nitrocellulose a metal non-reactive with the nitrocellulose solvent and copper sulphate non-reactive with respect to and soluble in the nitrocellulose solvent.

lose solvent, nitrocellulose, copper and copper sulphate.

FRED K. SHANKWEILER; ,WALTER E. GLOOR.

u 18. A nitrocellulose gel including a nitroc'ellu-. 

